943 results about "Ion-mobility spectrometry" patented technology

An asymmetric field ion mobility spectrometer with an ionization source for ionizing a sample media and creating ions. An ion filter is disposed in the analytical gap downstream from the ionization source for creating an asymmetric electric field to filter the ions. An ion flow generator for creating an electric field in a direction transverse to the asymmetric electric field and which propels the ions through the asymmetric electric field towards a detector.

An ion mobility spectrometer comprises an ion mobility cell (10) into which molecules of a sample to be analysed are introduced. The ion mobility cell (10) is doped with ions produced by a corona discharge ionisation source (40). In one mode of operation, the corona discharge ionisation source (40) operates to produce a continual dopant stream, and in a second mode of operation, the corona discharge ionisation source (40) produces dopant ions selectively. In the non-continuous mode of operation, the ion mobility cell (10) may be doped with chemical dopant ions instead, switching between the two dopant regimes being accomplished very rapidly. The ion mobility spectrometer is particularly suitable for the detection of explosive compounds and narcotics, the ion mobility spectrum of explosives doped with ions from the corona discharge ionisation source differing from the ion mobility spectrum of such explosive compounds doped with chemical dopants.

An improved tube for accepting gas-phase ions and particles contained in a gas by allowing substantially all the gas-phase ions and gas from an ion source at or greater than atmospheric pressure to flow into the tube and be transferred to a lower pressure region. Transport and motion of the ions through the tube is determined by a combination of viscous forces exerted on the ions by the flowing gas molecules and electrostatic forces causing the motion of the ions through the tube and away from the walls of the tube. More specifically, the tube is made up of stratified elements, wherein DC potentials are applied to the elements so that the DC voltage on any element determines the electric potential experience by the ions as they pass through the tube. A precise electrical gradient is maintained along the length of the stratified tube to insure the transport of the ions. Embodiments of this invention are methods and devices for improving the sensitivity of mass spectrometry or ion mobility spectrometers when coupled to atmospheric and above atmospheric pressure ionization sources. An alternate embodiment of this invention applies an AC voltage to one or more of the conducting elements in the laminate.

An improved ion source and portable analyzer for collecting and focusing dispersed gas-phase ions from a reagent source at atmospheric or intermediate pressure, having a remote source of reagent ions generated by direct or alternating currents, separated from a low-field sample ionization region by a stratified array of elements, each element populated with a plurality of openings, wherein DC potentials are applied to each element necessary for transferring reagent ions from the remote source into the low-field sample ionization region where the reagent ions react with neutral and/or ionic sample forming ionic species. The resulting ionic species are then introduced into the vacuum system of a mass spectrometer or ion mobility spectrometer. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when gas and liquid chromatographic separation techniques or probes containing samples are coupled to atmospheric and intermediate pressure photo-ionization, chemical ionization, and thermospray ionization sources.

An asymmetric field ion mobility spectrometer for breath analysis and a system for analysis of a sample of breath taken from a patient.

An improved ion source for collecting and focusing dispersed gas-phase ions from a reagent source at sub-atmospheric or intermediate pressure, having a remote source of reagent ions separated from a low-field sample ionization region by a barrier, comprised of alternating laminates of metal and insulator, populated with a plurality of openings, wherein DC potentials are applied to each metal laminate necessary for transferring reagent ions from the remote source into the low-field sample ionization region where the reagent ions react with neutral and/or ionic sample forming ionic species. The resulting ionic species are then introduced into the vacuum system of a mass spectrometer or ion mobility spectrometer. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when gas and liquid chromatographic separation techniques are coupled to sub-atmospheric and intermediate pressure photo-ionization, chemical ionization, and thermal-pneumatic ionization sources.

The invention includes an ion mobility spectrometer having a liquid filled drift chamber. The chamber has an ionization region partitioned from and an ion separation region by a reversible ion-migration block. An electrical field within the chamber allows ions to migrate toward the electrode collector. Passage of ions from the ionization region is triggered by reversing the block allowing ions to migrate into the ion separation region. The invention includes a method of ion mobility analysis in liquid phase. Ions are mobilized to migrate through a drift liquid and are detected at an end of a drift chamber. The invention also includes a method of generating ions in a sample. A sample containing molecules in a first solvent is introduced into a second solvent through a charged capillary where the electrically charged sample is electro-disperses to ionize the molecules.

The invention relates to a switchable ion mobility spectrometer (IMS) with ring electrodes divided into half-rings, which surround the drift chamber of the IMS. In a first operating condition, the two half-rings of each ring electrode are at the same potential and the various ring electrodes are at different potential varying monotonously along the drift path. In this way, ions are transported in the conventional manner along the drift path. In a second operating mode, the half-rings of the ring electrodes are at different potentials, by which the ions are each deflected toward one of the half-rings. The currents thus resulting are captured by the corresponding half-rings, amplified and an ion mobility spectrum is produced. A favorable design for the IMS can be used in many different modes of operation.

An ion separation instrument includes an ion source coupled to at least a first ion mobility spectrometer having an ion outlet coupled to a mass spectrometer. Instrumentation is further included to provide for passage to the mass spectrometer only ions defining a preselected ion mobility range. In one embodiment, the ion mobility spectrometer is provided with electronically controllable inlet and outlet gates, wherein a control circuit is operable to control actuation of the inlet and outlet gates as a function of ion drift time to thereby allow passage therethrough only of ions defining a mobility within the preselected ion mobility range. In another embodiment, an ion trap is disposed between the ion mobility spectrometer and mass spectrometer and is controlled in such a manner so as to collect a plurality of ions defining a mobility within the preselected ion mobility range prior to injection of such ions into the mass spectrometer. In yet another embodiment, an ion inlet of the ion trap may be electronically controlled relative to operation of the ion mobility spectrometer as a function of ion drift time to thereby allow passage therein only of ions defining a mobility within the preselected ion mobility range. The mass spectrometer is preferably a Fourier Transform Ion Cyclotron Resonance mass spectrometer, and the resulting ion separation instrument may further include therein various combinations of ion fragmentation, ion mass filtering, ion trap, charge neutralization and/or mass reaction instrumentation.

An ion trap-based system for chemical analysis includes an ion trap array. The ion trap array includes a plurality of ion traps arranged in a 2-dimensional array for initially confining ions. Each of the ion traps comprise a central electrode having an aperture, a first and second insulator each having an aperture sandwiching the central electrode, and first and second end cap electrodes each having an aperture sandwiching the first and second insulator. A structure for simultaneously directing a plurality of different species of ions out from the ion traps is provided. A spectrometer including a detector receives and identifies the ions. The trap array can be used with spectrometers including time-of-flight mass spectrometers and ion mobility spectrometers.

Method and apparatus for field ion mobility spectrometry for identification of chemical compounds in a sample by trajectory of sample ions in a transverse electric field.

The present invention relates generally to instrumentation and methodology for the characterization of chemical samples in solutions or on a surface which is based on modified ionization methods with or without adjustable pH and controllable H-D exchange in solution, an improved ion mobility spectrometer (IMS), a multi-beam ion pre-selection of the initial flow, and coordinated mobility and mass ion separation and detection using a single or several independent time-of-flight mass spectrometers for different beams with methods for fragmenting ion mobility-separated ions and multi-channel data recording

This invention is generally in the field of improved ion mobility spectrometry. The improvement lies in the use of periodic focusing electric fields that minimize the spatial spread of the migrating ions by keeping them in a tight radius about the axis of travel. The resulting enhancement in sensitivity is accomplished without a concomitant loss in resolution as would normally be expected when non-linear fields are used.

Correlation ion mobility spectrometry (CIMS) uses gating modulation and correlation signal processing to improve IMS instrument performance. Closely spaced ion peaks can be resolved by adding discriminating codes to the gate and matched filtering for the received ion current signal, thereby improving sensitivity and resolution of an ion mobility spectrometer. CIMS can be used to improve the signal-to-noise ratio even for transient chemical samples. CIMS is especially advantageous for small geometry IMS drift tubes that can otherwise have poor resolution due to their small size.

A method for analyzing analytes from a sample introduced into a Spectrometer by generating a pseudo random sequence of a modulation bins, organizing each modulation bin as a series of submodulation bins, thereby forming an extended pseudo random sequence of submodulation bins, releasing the analytes in a series of analyte packets into a Spectrometer, thereby generating an unknown original ion signal vector, detecting the analytes at a detector, and characterizing the sample using the plurality of analyte signal subvectors. The method is advantageously applied to an Ion Mobility Spectrometer, and an Ion Mobility Spectrometer interfaced with a Time of Flight Mass Spectrometer.

Various embodiments of a multi-dimensional ion mobility analyzer are disclosed that have more than one drift chamber and can acquire multi-dimensional ion mobility profiles of substances. The drift chambers of this device can, for example, be operated under independent operational conditions to separate charged particles based on their distinguishable chemical/physical properties. The first dimension drift chamber of this device can be used either as a storage device, a reaction chamber, and/or a drift chamber according to the operational mode of the analyzer. Also presented are various methods of operating an ion mobility spectrometer including, but not limited to, a continuous first dimension ionization methods that can enable ionization of all chemical components in the sample regardless their charge affinity.

A water trap system based on a thermoelectric cooling device is employed to remove a major fraction of the water from air samples, prior to analysis of these samples for chemical composition, by a variety of analytical techniques where water vapor interferes with the measurement process. These analytical techniques include infrared spectroscopy, mass spectrometry, ion mobility spectrometry and gas chromatography. The thermoelectric system for trapping water present in air samples can substantially improve detection sensitivity in these analytical techniques when it is necessary to measure trace analytes with concentrations in the ppm (parts per million) or ppb (parts per billion) partial pressure range. The thermoelectric trap design is compact and amenable to use in a portable gas monitoring instrumentation.

The present invention describes apparatuses and methods that provide energy to ions in a non-thermal manner. The elevated ion energy minimizes or eliminates interferences due to clustering with polar molecules, such as water. The energized ions are separated in an ion mobility spectrometer. During the ion transportation and separation process, the elevated energy level of ions prevents them from clustering with neutral molecule inside the spectrometer. The additional electric field component only causes ions to reach elevated energy level, whereby the spectrometer can preserve its normal performance, meanwhile avoiding interference from water and other neutral molecules. A RF electric field is applied to the ions in ionization, reaction and separation region of ion mobility spectrometers.